Psychosocial mechanisms through which obesity contributes to disease

Increasing evidence suggests that obesity is associated with psychological wellbeing in a bi-directional manner. That is to say that common psychological disorders such as chronic stress, anxiety and depression increase the risk of developing obesity, and at the same time, having obesity increases the risk of such disorders. The associations tend to be stronger in women than men, suggesting a moderating role of gender in the relationship.

<img src="https://ugc.futurelearn.com/uploads/assets/49/69/4969cb11-b5b6-4cd9-a072-5b93c4bab550.png" alt="Visceral obesity Sympathetic nervous system activation. Increased catecholamines; Hypothalamic-pituitary-adrenal axis activation. Increased cortisol; Health behaviour. Decreased physical activity, Increased caloric intake Stress, – Depression, – Anxiety”>

Obesity and stress are associated with dysregulation of several regulatory systems, including the hypothalamic-pituitary-adrenal axis (a neuroendocrine system) and the sympathetic nervous system, both of which are involved in the stress response. One of the main hormones involved in a chronic stress response is cortisol. Cortisol is known to cause redistribution of adipose tissue to the abdominal region ‘visceral obesity’ and increases appetite for energy-dense food¹. This means that increased stress can have a knock on effect of increasing visceral adiposity. Both chronic stress and increased visceral obesity activate stress-related pathways in a bi-directional pathway which can exacerbate patient symptoms of both conditions.

Higher prevalence of depression, stress and anxiety also come with related traits such as pessimism, low motivation, guilt and self-criticism² which, together with sleep disturbance,³ may feed into a feedback cycle of chronic pain. Depression has been shown to be a predictor of chronic pain, and chronic pain increases the risk of depression⁴. Pain is a complex phenomenon that is influenced by physical factors, but also by attitudes, beliefs, personality and social factors. The psychosocial experience of living with overweight and obesity has been shown to contribute to greater symptoms⁵. People with obesity also experience higher levels of fear of movement and pain catastrophising which can lead to more severe pain, greater physical disability and avoidance of activity⁶.